An MMA fighter is on trial in a Las Vegas court after he allegedly threatened to kill his porn star ex-girlfriend after he beat her mercilessly.

The trial began on Monday when the court heard that the MMA fighter War Machine beat his ex-girlfriend Christy Mackindayinday (Christy Mack) after finding her in bed with her then-boyfriend, Corey Thomas, as reported by Las Vegas Review-Journal.

The attack took place in August 2014. War Machine, born as Jonathan Paul Koppenhaver, reportedly walked into Mack’s bedroom. Koppenhaver first attacked a man in bed with Mack; he then began to attack his ex.

The MMA fighter pleaded “not guilty” to all 34 felony charges against him, including kidnapping, attempted murder and multiple counts of sexual assault..

After beating Mack, he told her that he couldn’t walk away without finishing her off.

“This is it. I’ve got to kill you now.”

The couple’s relationship was tumultuous from the beginning, according to sources close to the pair. According to Chief Deputy District Attorney Jacqueline Bluth , the two met at a shoot for Hustler magazine. Koppenhaver knew of Mack’s line of work, but it soon began to “disgust” him.